Not applicable.
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This invention is directed to crosslinked organic particles and suspensions thereof, and to methods for preparing the crosslinked organic particles and their suspensions. More particularly, this invention relates to spherical crosslinked organic particles that are highly dispersible in thermoplastic resins, thermosetting resins, paints, coatings, cosmetics, rubbers, and toners and carriers employed in electrostatic development. The invention additionally relates to very efficient methods for preparing crosslinked organic particles. Crosslinked organic particle suspensions have excellent handling properties and are highly blendable with other components. The invention also relates to very efficient methods for preparing such suspensions.
Non-thermally-softenable, solvent-insoluble crosslinked organic particles have an excellent resistance to heat, cold, and weathering, and excellent electrical properties, and are used as blocking inhibitors, cracking inhibitors, flatting agents, tactile sensation improvers, and lubricants for thermoplastic resins, thermosetting resins, paints, coatings, films, cosmetics, rubbers, and toners and carriers employed in electrostatic development. These crosslinked organic particles can be produced by (i) grinding or crushing a crosslinked organic material which produces irregularly shaped crosslinked organic particles; by (ii) producing solvent-insoluble crosslinked organic particles by dispersing a vinyl monomer and a compound bearing a plurality of unsaturated groups in a medium, and then inducing crosslinking by polymerization; and (iii) by dispersing epoxy resin in a medium and then crosslinking it using a curing agent to produce crosslinked organic particles.
However, such crosslinked organic particles suffer from poor dispersibility when blended into thermoplastic resins, thermosetting resins, paints, coatings, cosmetics, rubbers, and toners and carriers employed in electrostatic development.
It is therefore an object of the invention to provide spherical crosslinked organic particles that are highly dispersible in thermoplastic resins, thermosetting resins, paints, coatings, cosmetics, rubbers, and toners and carriers employed in electrostatic development. Another object is to provide highly efficient methods for preparing crosslinked organic particles. An additional object is to provide crosslinked organic particle suspensions that have excellent handling properties and are highly blendable with other components. Yet another object is to provide highly efficient methods for preparing such suspensions.
These and other features of the invention will become apparent from a consideration of the detailed description.
Not applicable.
Crosslinked organic particles according to the invention are spherical. They have an average particle size of 0.1 to 500 xcexcm and are afforded by an hydrosilylation-induced crosslinking of a fluid composition comprising:
(A) an organic compound that contains at least 2 aliphatically unsaturated bonds in each molecule,
(B) a silicon-containing organic compound that has at least 2 silicon-bonded hydrogen atoms in each molecule, and
(C) a catalyst for the hydrosilylation reaction.
Crosslinked organic particle suspensions of the invention contain water, an emulsifying agent, the crosslinked organic particles, and the particles are dispersed in the water.
One method for preparing the crosslinked organic particles is by emulsifying a fluid composition comprising:
(A) an organic compound that contains at least 2 aliphatically unsaturated bonds in each molecule,
(B) a silicon-containing organic compound that has at least 2 silicon-bonded hydrogen atoms in each molecule, and
(C) a catalyst for the hydrosilylation reaction,
in water using an emulsifying agent, crosslinking the fluid composition by carrying out hydrosilylation, and thereafter removing the water.
Another method for preparing crosslinked organic particles comprises emulsifying a fluid composition of components (A) and (B) in water using an emulsifying agent, thereafter adding component (C), then crosslinking the composition by carrying out hydrosilylation, and finally removing the water.
One method for preparing crosslinked organic particle suspensions according to the invention is by emulsifying a fluid composition comprising:
(A) an organic compound that contains at least 2 aliphatically unsaturated bonds in each molecule,
(B) a silicon-containing organic compound that has at least 2 silicon-bonded hydrogen atoms in each molecule, and
(C) a catalyst for the hydrosilylation reaction,
in water using an emulsifying agent, and crosslinking the fluid composition by carying out hydrosilylation.
Another method for preparing crosslinked organic particle suspensions of the invention is by emulsifying a fluid composition of components (A) and (B) in water using an emulsifying agent, thereafter adding component (C), and then crosslinking the composition by carrying out hydrosilylation.
Crosslinked organic particles according to the invention are spherically-shaped crosslinked organic particles, and they are provided by an hydrosilylation-induced crosslinking of a fluid composition comprising components (A) through (C) described above. These particles should have an average particle size in the range from 0.1 to 500 xcexcm, and preferably have an average particle size in the range from 0.1 to 200 xcexcm. It is quite difficult to prepare crosslinked organic particles with an average particle size below the lower limit of the given range. Crosslinked organic particles with an average particle size exceeding the upper limit of the given range exhibit an increasingly impaired dispersibility when blended into organic resins, paints, coatings, and cosmetics.
Organic compound (A) contains at least 2 aliphatically unsaturated bonds in each molecule. The aliphatically unsaturated group in (A) can be a group present in a molecular chain terminal position, or it can be present in a pendant position on the molecular chain. It can be alkenyl such as vinyl, allyl, butenyl, and pentenyl; alkynyl such as ethynyl; or a cyclic unsaturated group such as the norbornene group or dicyclopentadienyl. The aliphatically unsaturated group can also be a group within the molecular chain, in which case it can be an enylene group like vinylene or propenylene. Groups present in a terminal or pendant position on the molecular chain such as vinyl and allyl are preferred for the aliphatically unsaturated group in (A). The state of (A) is not critical, and component (A) can be a solid or a liquid, with a liquid being preferred. When component (A) is a solid, it will be necessary to preliminarily dissolve it in component (B) when such dissolution is possible, or component (A) would have to be dissolved in an organic solvent. While the molecular weight of component (A) is not critical, its average molecular weight is preferably in the range from 50 to 50,000.
Component (A) can be exemplified by dienes such as pentadiene, hexadiene, heptadiene, octadiene, nonadiene, cyclopentadiene, and cyclooctadiene; aromatic dienes such as divinylbenzene; ethers such as diallyl ether, triethylene glycol divinyl ether, cyclohexane dimethanol divinyl ether, and 1,2-divinyl glycol; diene esters such as diallyl isophthalate, diallyl phthalate, diallyl terephthalate, diallyl maleate, and triallyl trimellitate; oligomers from polymerization of any of the preceding; olefin oligomers that contain at least 2 aliphatically unsaturated bond-containing groups in each molecule, produced by polymerization of an olefin such as ethylene, propylene, butene, isobutene, pentene, or hexene; oligomers from polymerization of an alkenyl-functional acrylic monomer such as allyl (meth)acrylate, butenyl (meth)acrylate, methylbutenyl(meth)acrylate, methylpropenyl(meth)acrylate, heptenyl (meth)acrylate, and hexenyl (meth)acrylate; oligomers from copolymerization of acrylic monomer as listed above with a monomer such as methyl(meth)acrylate, ethyl(meth)acrylate, butyl(meth)acrylate, ethylhexyl(meth)acrylate, lauryl(meth)acrylate, styrene, xcex1-methylstyrene, maleic acid, vinyl acetate, or allyl acetate; oligomers from reaction of an alkenyl isocyanate such as allyl isocyanate, (meth)acryloyl isocyanate, and 2-isocyanatoethyl (meth)acrylate) or an alkenyl-functional carboxylic acid anhydride such as itaconic anhydride, maleic anhydride, or tetrahydrophthalic anhydride, with an oligomer produced by copolymerization of such a monomer as referenced above and a hydroxyl-functional acrylic monomer such as 2-hydroxyethyl (meth)acrylate, 2-hydroxypropyl (meth)acrylate, or 4-hydroxybutyl (meth)acrylate; oligomers from reaction of an alkenyl alcohol such as allyl alcohol, butenol, 2-(allyloxy) ethanol, glycerol diallyl ether, cyclohexene methanol, methylbutenol, and oleyl alcohol with an oligomer produced by polymerization of isocyanate-functional acrylic monomers such as (meth)acryloyl isocyanate and 2-isocyanatoethyl (meth)acrylate), or with an oligomer produced by copolymerization of such an isocyanate-functional acrylic monomer with a monomer as referenced above; oligomers from reaction of an alkenyl-functional epoxy compound such as glycidyl (meth)acrylate and allyl glycidyl ether with an oligomer from polymerization of a carboxyl-functional monomer such as (meth)acrylic acid, itaconic acid, and maleic acid or with an oligomer from copolymerization of such carboxyl-functional monomers with a monomer as referenced above; polyethers from the ring-opening polymerization of allyl glycidyl ether using ethylene glycol as an initiator; polyethers from the ring-opening polymerization of vinylcyclohexane-1,2-epoxide using butanol, allyl alcohol, or propargyl alcohol as an initiator; alkenyl-functional polyesters from reaction of an alkenyl alcohol as referenced above, a polyhydric alcohol such as ethylene glycol, propylene glycol, 1,6-hexanediol, diethylene glycol, neopentyl glycol, the neopentyl glycol ester of hydroxypivalic acid, and trimethylolpropane, and a polybasic acid such as phthalic anhydride, isophthalic acid, terephthalic acid, adipic acid, azelaic acid, and trimellitic acid. Component (A) is preferably a diene, diene oligomer, or polyether.
Silicon-containing organic compound (B) contains at least two silicon-bonded hydrogen atoms in each molecule. Component (B) preferably has a viscosity at 25xc2x0 C. in the range from 1 to 100,000 mPaxc2x7s, and particularly preferably in the range from 1 to 10,000 mPaxc2x7s. Silicon-containing organic compound (B) can be exemplified by organohydrogenpolysiloxanes, and organic polymers that contain diorganohydrogensilyl groups, with organohydrogenpolysiloxanes being preferred.
Organohydrogenpolysiloxanes encompassed by component (B) can have a straight-chain, branched-chain, cyclic, network, or partially branched straight-chain molecular structure, and can be exemplified by trimethylsiloxy-endblocked methylhydrogenpolysiloxanes; trimethylsiloxy-endblocked dimethylsiloxane-methylhydrogensiloxane copolymers; trimethylsiloxy-endblocked dimethylsiloxane-methylhydrogensiloxane-methylphenylsiloxane copolymers; dimethylhydrogensiloxy-endblocked dimethylpolysiloxanes; dimethylhydrogensiloxy-endblocked dimethylsiloxane-methylphenylsiloxane copolymers; dimethylhydrogensiloxy-endblocked methylphenylpolysiloxanes; organopolysiloxane copolymers containing R3SiO1/2, R2HSiO1/2, and SiO4/2 siloxane units; organopolysiloxane copolymers containing R2HSiO1/2 and SiO4/2 siloxane units; organopolysiloxane copolymers containing RHSiO2/2 siloxane units and RSiO3/2 or HSiO3/2 siloxane units; and mixtures of two or more of such organopolysiloxanes.
The R group in these formulas represents non-alkenyl monovalent hydrocarbyl groups and can be an alkyl group such as methyl, ethyl, propyl, butyl, pentyl, hexyl, and heptyl; aryl such as phenyl, tolyl, xylyl, and naphthyl; aralkyl such as benzyl and phenethyl; and halogenated alkyl groups such as chloromethyl, 3-chloropropyl, and 3,3,3-trifluoropropyl.
Diorganohydrogensilyl-functional organic polymers encompassed by component (B) can be exemplified by oligomers from copolymerization of dimethylhydrogensilyl-functional acrylic monomers such as dimethylhydrogensilyl (meth)acrylate and dimethylhydrogensilylpropyl (meth)acrylate with monomers such as methyl (meth)acrylate, ethyl (meth)acrylate, butyl (meth)acrylate, ethylhexyl (meth)acrylate, lauryl (meth)acrylate, styrene, xcex1-methylstyrene, maleic acid, vinyl acetate, and allyl acetate.
The content of component (B) in the composition provides preferably from 0.5 to 500 weight parts (B), and particularly preferably from 1 to 100 weight parts (B), in each case, for each 100 weight parts of component (A). The possibility of inadequate crosslinking arises when the component (B) content in the composition falls below the given lower limit of the range. A composition in which the component (B) content exceeds the upper limit of the range risks the evolution of hydrogen gas due to excess silicon-bonded hydrogen.
Component (C) is a catalyst for the hydrosilylation reaction. It should be a catalyst that promotes the hydrosilylation reaction in the composition, and thereby induce the crosslinking thereof. Component (C) is exemplified by platinum catalysts, rhodium catalysts, and palladium catalysts, with platinum catalysts being preferred. Platinum catalysts can be exemplified by Pt-on-finely divided silica, Pt-on-finely divided carbon, chloroplatinic acid, alcohol solutions of chloroplatinic acid, olefin complexes of platinum, alkenylsiloxane complexes of platinum, and carbonyl complexes of platinum.
The content of component (C) in the composition is not critical, but component (C) should be added in a catalytic quantity sufficient to promote the hydrosilylation reaction in the composition. When a platinum catalyst is used as component (C), it is preferably added in a quantity that will provide from 1xc3x9710xe2x88x927 to 1xc3x9710xe2x88x923 weight parts of platinum metal for each 100 weight parts of the total of components (A) and (B). Adequate crosslinking may not occur when the component (C) content in the composition is below the lower limit of the range. The use of quantities in excess of the upper limit of the range is not particularly effective, and such quantities are not economical.
Optional components that may be added to the composition are exemplified by inhibitors for controlling the hydrosilylation reaction; reinforcing fillers such as precipitated silica, fumed silica, calcined silica, and fumed titanium oxide; semi-reinforcing fillers such as crushed quartz, diatomaceous earth, aluminosilicates, iron oxide, zinc oxide, and calcium carbonate; any of the preceding fillers after surface treatment with an organosilicon compound such as hexamethyldisilazane, trimethylchlorosilane, polydimethylsiloxane, or polymethylhydrogensiloxane.
Noncrosslinking oils can also be admixed into the composition. Noncrosslinking oils can be exemplified by noncrosslinking silicone oils such as trimethylsiloxy-endblocked dimethylpolysiloxanes, trimethylsiloxy-endblocked methylphenylpolysiloxanes, trimethylsiloxy-endblocked dimethylsiloxane-methylphenylsiloxane copolymers, trimethylsiloxy-endblocked dimethylsiloxane-methyl(3,3,3-trifluoropropyl) siloxane copolymers, cyclic dimethylsiloxanes, and cyclic methylphenylsiloxanes. Other noncrosslinking organic oils which can be used are alkanes such as hexane and heptane, aromatic hydrocarbons such as benzene and toluene, chlorinated hydrocarbons such as carbon tetrachloride and methylene chloride, ketones such as methyl isobutyl ketone, alcohols such as undecyl alcohol, ethers such as dibutyl ether, esters such as isopropyl laurate and isopropyl palmitate, liquid paraffin, isoparaffin, hexyl laurate, isopropyl myristate, myristyl myristate, cetyl myristate, 2-octyldecyl myristate, isopropyl palmitate, 2-ethylhexyl palmitate, butyl stearate, decyl oleate, 2-octyldodecyl oleate, myristyl lactate, cetyl lactate, lanolin acetate, stearyl alcohol, cetostearyl alcohol, oleyl alcohol, avocado oil, almond oil, olive oil, cacao oil, jojoba oil, sesame oil, safflower oil, soy oil, camellia oil, squalane, persic oil, castor oil, mink oil, cottonseed oil, coconut oil, egg yolk oil, lard, glycol ester oils such as polypropylene glycol monooleate and neopentyl glycol 2-ethylhexanoate, polyhydric alcohol ester oils such as isostearate triglyceride and cocofatty acid triglycerides, and polyoxyalkylene ether oils such as polyoxyethylene lauryl ether and polyoxypropylene cetyl ether. The noncrosslinking oil preferably has a viscosity at 25xc2x0 C. in the range from 1 to 100,000,000 mpaxc2x7s, and particularly preferably in the range from 2 to 10,000,000 mPaxc2x7s. The noncrosslinking oil is preferably present in the composition in an amount that provides from 0.1 to 5,000 weight parts of the noncrosslinking oil for each 100 weight parts of the composition, excluding the noncrosslinking oil.
Suspensions according to the invention contain the crosslinked organic particles as described above, an emulsifying agent, and water, and the particles are dispersed in the water. The crosslinked organic particles described above are used as the crosslinked organic particles in these suspensions. The emulsifying agent functions to improve the stability of the crosslinked organic particles in water. The emulsifying agent can be a cationic surfactant, an anionic surfactant, an amphoteric surfactant, a nonionic surfactant, or a mixture of surfactants.
Cationic surfactants can be exemplified by the salts of primary, secondary, and tertiary amines, alkyltrimethyl ammonium salts, dialkyldimethyl ammonium salts, tetraalkyl ammonium salts, trialkylbenzyl ammonium salts, alkylpyridinium salts, N,N-dialkylmorpholinium salts, and the salts of polyethylene polyamine aliphatic amides.
Anionic surfactants can be exemplified by the salts of aliphatic acids, the salts of alkylbenzene sulfonic acids, the salts of alkylnaphthalene sulfonic acids, the salts of alkylsulfonic acids, the salts of xcex1-olefin sulfonic acids, the salts of dialkyl sulfosuccinates, xcex1-sulfonated aliphatic acid salts, N-acyl-N-methyltaurates, alkyl sulfate salts, sulfated oils, polyoxyethylene alkyl ether sulfate salts, polyoxyethylene alkylphenyl ether sulfates, polyoxyethylene styrenated phenyl ether sulfates, alkyl phosphates, polyoxyethylene alkyl ether phosphates, polyoxyethylene alkylphenyl ether phosphates, and formaldehyde condensates of naphthalene sulfonates.
Amphoteric surfactants can be exemplified by N,N-dimethyl-N-alkyl-N-carboxymethyl ammonium betaines, N,N-dialkylamino alkylene carboxylates, N,N,N-trialkyl-N-sulfoalkylene ammonium betaines, N,N-dialkyl-N,N-bispolyoxyethylene ammonium sulfate ester betaines, and 2-alkyl-1-carboxymethyl-1-hydroxyethyl imidazolinium betaines.
Nonionic surfactants can be exemplified by polyoxyethylene alkyl ethers, polyoxyethylene alkenyl ethers, polyoxyethylene alkylphenyl ethers, polyoxyethylene polystyryl phenyl ethers, polyoxyethylene-polyoxypropylene glycols, and polyoxyethylene-polyoxypropylene alkyl ethers; aliphatic acid partial esters of polyhydric alcohols such as aliphatic acid esters of sorbitan, aliphatic acid esters of glycerol, aliphatic acid esters of decaglycerol, aliphatic acid esters of polyglycerol, aliphatic acid esters of ethylene glycol/pentaerythritol, and aliphatic acid esters of propylene glycol/pentaerythritol; polyoxyethylene adducts of aliphatic acid partial esters of polyhydric alcohols such as polyoxyethylene adducts of aliphatic acid esters of sorbitan, and polyoxyethylene adducts of aliphatic acid esters of glycerol; polyoxyethylene/aliphatic acid esters, aliphatic acid esters of polyglycerol, polyoxyethylated castor oil, diethanolamides of aliphatic acids, polyoxyethylene alkylamines, aliphatic acid partial esters of triethanolamine, trialkylamine oxides, and polyoxyalkylene-functional organopolysiloxanes. Use of a nonionic surfactant is preferred.
The content of the emulsifying agent is preferably from 0.1 to 20 weight parts, and particularly preferably from 0.5 to 10 weight parts, in each case, for each 100 weight parts of the crosslinked organic particles.
The water content is not critical but water preferably should constitute 5 to 99 weight % of the suspension, and more preferably 10 to 80 weight %.
Such suspensions may also contain other components including additives for stabilizing the dispersion or adjusting the viscosity such as ethanol or any water-soluble polymer such as xanthan gum, guar gum, carboxymethyl cellulose, polyvinyl alcohol, polyvinylpyrrolidone, carboxyvinyl polymers, hydroxyethyl cellulose, and polyoxyethylene glycol distearate; film-forming agents such as polymers of radically polymerizable (meth)acrylic monomers, copolymers of silicone compounds with radically polymerizable (meth)acrylic monomers, poly(N-acylalkylene imine)s, poly(N-methylpyrrolidone)s, and silicone resins that contain groups such as fluorinated organic groups, the amino, or silanol group; oxidation inhibitors such as BHA, BHT, and xcex3-orizanol; antifreezes such as ethanol, isopropyl alcohol, 1,3-butylene glycol, ethylene glycol, propylene glycol, and glycerol; antimicrobials and preservatives such as triclosan and triclocarban; pearlescent agents; chelating agents such as ethylene diamine tetraacetic acid, citric acid, ethane-1-hydroxy-1,1-diphosphonic acid, and their salts; UV absorbers including benzophenone derivatives such as 2-hydroxy-4-methoxybenzophenone, benzotriazole derivatives such as 2-(2xe2x80x2-hydroxy-5xe2x80x2-methylphenyl) benzotriazole, and cinnamic acid esters; colorants such as chromatogens, dyes, and pigments; spray-enabling agents; vitamins; hair tonics; growth promoters; hormones; fragrances; and perfumes.
These crosslinked organic particles and their suspensions are useful as components for imparting properties such as lubricity, softness, and flexibility to lubricants, cleaning agents, flatting agents, cosmetics, and materials employed in electrostatic development such as toners and carriers. They can also be used as components for imparting such properties as flatness, softness, and flexibility to paints and coatings; and as components for imparting such properties as lubricity and impact resistance to thermosetting resins and thermoplastic resins.
One method for preparing suspensions is by emulsifying a fluid composition containing components (A), (B), and (C) in water using emulsifying agent, and then crosslinking the composition by effecting hydrosilylation.
Another method for preparing suspensions is by emulsifying a fluid composition containing components (A) and (B) in water using emulsifying agent, thereafter adding component (C), and subsequently crosslinking the composition by effecting hydrosilylation.
Components (A), (B), and (C) used in these methods are the same components as described above. The emulsifying device used for the emulsifying agent-supported emulsification of the components (A)xe2x88x92(C) composition in water, for the emulsifying agent-supported emulsification of the components (A)+(B) composition in water, and for the addition of component (C) to the component (A)+(B) composition, can be exemplified by homomixers, paddle mixers, Henschel mixers, homodispersers, colloid mills, propeller-type stirrers, homogenizers, inline continuous emulsifiers, ultrasound emulsifiers, and vacuum mills.
Surfactants as described above can be used as the emulsifying agent in these methods, and the use of a nonionic surfactant is particularly preferred. The emulsifying agent is preferably added at from 0.1 to 20 weight parts, and particularly preferably at from 0.5 to 10 weight parts, in each case, for each 100 weight parts of the total of components (A) to (C). The amount of water is not critical, but water preferably should be present in an amount of from 5 to 99 weight % of the overall emulsion, and more preferably from 10 to 80 weight % of the overall emulsion.
The crosslinked organic particle suspension can be produced by heating the resulting emulsion of the fluid composition, or by holding this emulsion at room temperature to effect hydrosilylation-induced crosslinking of the water-dispersed fluid composition.
The resulting crosslinked organic particles have a spherical shape, and they should have an average particle size in the range from 0.1 to 500 xcexcm, and preferably in the range from 0.1 to 200 xcexcm. It is quite difficult to prepare crosslinked organic particles with an average particle size below the lower limit of the given range. Crosslinked organic particles with an average particle size exceeding the upper limit of the given range exhibit an increasingly impaired dispersibility when blended into organic resins, paints, coatings, and cosmetics.
The methods according to the invention include removing water from the crosslinked organic particle suspension. The technique to remove water is exemplified by spraying the suspension into a hot gas current, freeze-drying the suspension, and addition of salt to the suspension to aggregate the crosslinked organic particles, followed by thermal drying of the separated crosslinked organic particle slurry. The crosslinked organic particles are preferably used in a suspension form since the suspension form offers particularly good handling characteristics and blendability with other components.